All Questions

4
votes
2answers
163 views

From the General Thrust Equation towards Tsiolkovsky, how to explain dropping these terms along the way?

The NASA Glen Research Center tutorial page Rocket Thrust Equation links to the General Thrust Equation page which starts with: Which transcribes into MathJax as: $ \ \ \ F = \dot{m}_e V_e - \...
0
votes
1answer
14 views

When an how will BepiColombo and JAXA’s Mercury Magnetospheric Orbiter separate?

With all the fanfare about BepiColombo (mine included) I didn't realize that there were two spacecraft on this launch. From Spaceflight Now's Ariane 5 launches two satellites on 7-year voyage to ...
3
votes
1answer
27 views

An alternative to gold plated record?

Voyager's Golden record was recorded in an analog way. Its lifespan perhaps 1 billion years. Let's say that I would like to send an spacecraft with information recorded in digital. Which alternatives ...
0
votes
0answers
15 views

Is it possible to restart life Mars? [duplicate]

I have learnt that the reason for no life existing on Mars was due to absence of a magnetic field strong enough to ward off incoming solar radiation. We could just instate an artificial one if that ...
-1
votes
1answer
44 views

Gravity cancellation point [on hold]

Here is a question from ANTHE: an exam in India. The question is:Two point masses M and 3M are placed at a L distance apart. Another point mass m is between on the line joining them so that the net ...
1
vote
0answers
14 views

Yet another OSIRIS! Has the DLR/GOM Space test of the cubesat optical communications link happened yet?

Speaking of "all things OSIRIS" I just ran across the OSIRIS optical communications system for cubesats and smallsats. OSIRIS (Optical Space Infrared Downlink System) highly compact optical ...
2
votes
0answers
19 views

Career in Planetary Science with an Engineering background

I am passionate in achieving a career in Planetary Science. I have a bachelor's degree in mechanical engineering background with an average academic record. I want to pursue a career in Planetary ...
2
votes
1answer
59 views

How much wax is on the Moon? (Lunar Roving Vehicles)

I found the Cody's Lab videos from Scott Manley's video as described in this answer. Browsing through I learned from the first 30 seconds of Hot Wax Bottle? that the phase change of wax was used on ...
2
votes
2answers
40 views

Terraforming Mars - would Mars lose its water?

If we were to terraform Mars would Mars slowly lose its water i.e., some of the water would sink deep into the dry Martian crust or combine with other elements in the soil? Mars has been dry for ...
3
votes
1answer
53 views

Help understanding BepiColombo's weak capture at Mercury's L1 and need for delta-differential one-way range measurements

This four-minute BBC podcast Mission to Mercury: BepiColombo spacecraft ready for launch highlights several challenges of the BepiColombo mission, including its orbital-mechanical aspects and is worth ...
1
vote
0answers
20 views

If Cassini's final flyby of Saturn's moon Titan is the 127th Titan flyby, why is it called “T-126”?

Cassini's final flyby of Titan in April 2017 sealed it's fate in September of that year. This is described further in answers to What force is bringing Cassini down into Saturn's atmosphere in another ...
3
votes
0answers
75 views

Radial variation of atmospheric pressure in rotating O'Neill cylinder-like ship? (Rendezvous with Rama)

Sir Arthur C. Clarke was a science writer as well as a prolific writer of science fiction (including hard SF*), and his stories usually had a substantial footing in science. His book Rendezvous with ...
3
votes
0answers
44 views

How many tons of water is needed to surround ISS's living modules, so the rate of radiation exposure will be the same as on the surface of Earth?

If I understand correctly, it wasn't done because it's very expensive ($ per lbs) and there are no launch systems powerful enough for that? Also, could you please provide formulas and calculations? I ...
-2
votes
2answers
162 views

Why should the Kármán line not be a realistic, curved one around the Earth?

Why not consider the Kármán line as a curved one that follows the curvature of the Earth ? According to Wikipedia's article about the Kármán line: The Kármán line is the altitude where the speed ...
2
votes
0answers
14 views

What advances are there in heat-resistant materials for engines?

As one of the difficulties in engine design is to prevent it from melting, one can expect research to be conducted on what materials to use for thrust chamber and nozzle. Many engines seem to use ...
3
votes
0answers
32 views

What is meant by chamber pressure in rocket engines?

Is "chamber pressure" the pressure at the tip of the injector, or the pressure before combustion inside the chamber, or the pressure after combustion inside the chamber?
0
votes
0answers
30 views

How many solar system bodies have had coherent radio transponders?

A transponder amplifies, (often) frequency-shifts, and rebroadcasts a received signal. Old-style telephone and TV distribution satellites in GEO used simple transponders to rebroadcast the uplinked ...
16
votes
1answer
2k views

Did NASA's Borg Collective-designed antennas work? Have similar designs ever been used in spacecraft beyond testing?

This interesting answer to the question Do antenna farms on spacecraft make any sense or are they purely aesthetic? in Worldbuilding SE links to the NASA Ames page 'Borg' Computer Collective Designs ...
1
vote
1answer
23 views

How will “InSight's onboard communications gear perform a radio-science experiment to shed further light on Mars' innards?” (Space.com)

The Space.com article How NASA Mars Lander's 'Steampunk' Claw Will Work (Video) says: InSight's mission aims to provide a detailed look at Mars' interior structure and composition. The lander ...
1
vote
0answers
33 views

Temperature indicators/labels on space debris?

There was a picture in this question about space debris on shore. Seems to be a part of a Falcon 9. The round stickers are used for temperature control. Similar labels are sold by some companies, for ...
5
votes
1answer
978 views

What would be the specific impulse of a continuous nuclear fusion drive?

Let's assume problems of running sustained nuclear fusion are overcome (be it by making the mechanism highly energy-positive, or just supplying all the energy deficit externally, like beamed power.) ...
8
votes
1answer
535 views

Who performs the docking procedure?

In the Apollo moon missions when the LEM returned to the CSM, which astronaut performed the docking procedure? Did the command module pilot just hold a fixed position while the astronaut flying the ...
1
vote
0answers
47 views

Would the atmosphere of Mars become less dusty if the ice deposit in Utopia Planitia could be uncovered?

In 2016 a large ice deposit has been found within the Utopia Planitia region on Mars by the SHARAD instrument on board of the Mars Reconnaissance Orbiter. The thickness of the deposit ranges from 80 ...
1
vote
0answers
36 views

Venus Exploration [duplicate]

While reading an article about a possible "Cloud City" on Venus I was taken by the following statement: Venus’s atmosphere is mainly carbon dioxide and thick clouds of sulfuric acid cover the ...
5
votes
1answer
81 views

What is the typical mach number at which the peak dynamic pressure occurs?

Is there any mach number range (say 0.8-1.4) where the maximum Q of the rocket should occur?
3
votes
0answers
101 views

Wet space junk and flotsam washing up on shore, will it get worse, is there a plan to mitigate?

This comment links to this collectspace.com post: Three business executives vacationing (?) in the Bahamas came across part of a SpaceX Falcon 9 fairing that washed ashore. They shared their find ...
6
votes
1answer
164 views

Any risk from Soyuz 22-ton fuel dump?

Following the recent mishap with the Soyuz, Kazakhstan's deputy minister for defense and the aerospace industry said that about 22 tons of fuel (kerosene and liquid oxygen) were dumped/fell over the ...
1
vote
1answer
53 views

NASA's Curiosity Rover - Carbon Isotope Ratio of Methane?

The following is taken from Sinha & Rral , 2015: "NASA's Curiosity rover has the capability to search for organic compounds and to identify the chemical and isotopic composition of the Martian ...
2
votes
0answers
39 views

NRLMSISE atmospheric drag model in GMAT

I'm using GMAT (R2018a) software for orbital propagation and now testing the atmospheric drag. There are only 2 options: JacciaRoberts and MSISE90. Is there a way to add NRLMSISE00 to the options? ...
2
votes
1answer
98 views

What is the highest gimbal range ever used on an engine?

This answer here mentions the STS-94's ability to gimbal up to 20 degrees in all directions, that got me thinking, what exactly is the maximum ever feasibly implemented? I've seen a lot of information ...
4
votes
0answers
55 views

How much would mass-production impact the cost of solid-fuel rockets?

Let's imagine that, for some arbitrary reason, solid-fuel rocket stages were needed and built en masse in factories, like planes or even like cars. How much would it drive down the cost of an ...
5
votes
1answer
85 views

Unknown Moons and Planetary Flybys

I’ve a question for any trajectory experts out there: The Pioneer and Voyager probes discovered new moons during their flybys of our four giant planets (and indeed rings). These didn’t come as much ...
0
votes
0answers
47 views

How was the thrust for the STS-94 launch and other space shuttle launches balanced? [duplicate]

I've been looking at of the STS-94 skylab launch and other launching involving asymmetrical rocket launch vehicles, mostly because I've never been able to design something similar in KSP with ...
0
votes
0answers
35 views

Orbital Strap-on Boosters?

Have there been any proposals to launch a "space station" type of assembly into LEO, then send up some engines to get it to be able to move again? Take for instance something akin to the ISS, but much ...
5
votes
0answers
93 views

What did Karman's original “Karman line” calculations look like?

Looking for the atmospheric parameters (density for example) and vehicle parameters (CL for example) as well as formulae that were used in the original calculation. Primary sources strongly preferred,...
6
votes
1answer
182 views

Did the Soviet Union put an unmanned satellite in “very low orbit”above the Kármán line which used aerodynamic attitude control?

This interesting, archived page https://www.webcitation.org/618QHms8h?url=http://www.fai.org/astronautics/100km.asp which I found in this answer, says: Later in the same decade (or very early in ...
29
votes
2answers
6k views

How did the X-15 control attitude above the Kármán line?

This interesting, archived page https://www.webcitation.org/618QHms8h?url=http://www.fai.org/astronautics/100km.asp which I found in this answer, says: In the early 1960´s, the U.S. X-15 Aircraft ...
4
votes
1answer
140 views

How are rocket propellants ignited repeatedly without the ignition source melting

I know that SpaceX's Falcon uses TEA-TEB instead of a physical igniter, but if I remember correctly, NASA has never used hypergolic propellants to start their restart-able engines. How does NASA's (or ...
0
votes
1answer
104 views

Analytical approximations for the shapes of these plots of ISP vs nozzle diameter? (Raptor engine)

A comment on the currently unanswered question Is there an authoritative catalog for rocket launch identifiers? led me to this Github page which links to r/spacexlounge on which currently appears a ...
5
votes
2answers
138 views

Orbital propagation: atmospheric drag

I'm developing the numerical orbital propagator. I've already implemented the Newtonian gravity (Earth, Sun, Moon), Earth harmonics, SRP and relativistic effect. The software is compared with GMAT ...
14
votes
3answers
6k views

Why not keep the engine for multi-stage rockets?

Rocket engines are a huge weight in a multi-stage rocket. and they are stacked like so: Fairing/Payload Fuel Engine -- Seperator -- Fuel Engine and so on, which means multiple engines. Is there ...
1
vote
1answer
116 views

How accurate can a satellite's orbit be?

How precise can an artificial satellite be when it comes to following the exact orbit in relation to Earth or hitting the same point above Earth in orbit? Which orbit would be the most stable for this?...
0
votes
0answers
70 views

What is the speed of ISS relative to ground surface?

Is it 7660 m/s or (7660-460)m/s? If it is the former then the ISS orbits about the Earth at 8120 m/s. I think it should be (7660-460)m/s relative to ground based on this orbital period formula, $$T=...
1
vote
1answer
84 views

NASA's Mars helicopter blade & weight

I've been really interested in NASA's Mars helicopter and have been reading bits of articles on that recently. But I have a few questions I hope people can help me understand — in this article, it ...
7
votes
1answer
134 views

Why does in-flight mission abort often ends in ballistic high-$g$ reentry?

I am seeing a lot of references to the “ballistic reentry” mode of the crew return vehicle in relation to the abort during the powered ascent stage. In partiulat, the recent crewed Soyuz MS-10 abort ...
0
votes
0answers
33 views

Is there an orbit that follows the polar cusp?

What orbit would follow the polar cusp in the magnetosphere demonstrated in the picture below in red? What altitude would be needed to stay in the polar cusp following the Sun?
0
votes
0answers
47 views

Has the answer to PopSci's question “How Many Years Does The Space Station Have Left?” been published?

This answer to the question Why does the ISS have to be destroyed? begins It doesn't, not really, but there will come a time when it will simply not be worth keeping it up. and mentions a study, ...
2
votes
1answer
99 views

What is the likely plan to deorbit the ISS given its size and shape?

The ISS is nearing its final years and this question spurred me to ask a follow up. Let's say that the various countries grab whatever equipment/modules they provided in assembly and the ISS is ...
1
vote
1answer
62 views

When was the ISS's “SPEED LIMIT 17500 MPH” sign originally posted?

When was the ISS's "SPEED LIMIT 17500 MPH" sign originally posted? above: "STS110-353-012 (8-19 April 2002) --- Astronaut Ellen Ochoa, STS-110 mission specialist, poses by the speed limit signs in ...
25
votes
4answers
10k views

How exactly will the ISS die in 2025?

According to: ”Moreover, the ISS end of life might come in 2025, and assuming you need a few years to graduate, more to get a degree, work experience, get hired, do the training... The ISS might ...

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